Multi-plan formulation of hydropower generation considering uncertainty of wind power

摘要

Being driven by wind, which has the characteristics of intermittency, the output power of a wind farm is fluctuating and difficult to forecast accurately, which imposes higher requirements on the schedule of the power system. In this paper, the fluctuation characteristics of wind power during the adjacent time interval is accurately captured through statistical analysis of the historical data of the wind farm. Then, a two-layer nested model for a hydro-wind complementary system is formulated to improve the guidance for the daily generation scheduling. In the outer layer, load distribution schemes for each station are determined using the heuristic successive cutting load method. In the inner layer, the water consumption tolerance is introduced so that the original inner model is modified into a multi-plan model of in-station economic operation, which is solved with the multi-plan solution of the dynamic programming method. A cascade hydropower station located in Qing River of China is chosen for a detailed case study. The operational results indicate the following: (1) In hydro-wind complementary system, the water consumption tolerance of a hydropower station based on the fluctuation distribution of wind power is adaptable to wind power uncertainty; (2) Using the multi-plan solution of the dynamic programming method, the optimal scheduling of the load distribution of a hydropower station based on water consumption tolerance provides a larger decision-making space for economic operation of the hydropower station; (3) The adjustable range of unit is related to the range of water head, output, and vibration zone of the hydropower station. A small change in water consumption can bring about a large change in the adjustable range; (4) The daily generation scheduling considering the adjustable range of unit can reserve the adjustment margin of the unit before the implementation of the plan, reduce the number of times the unit passes through the vibration zone during actual operation, and enhance the stability of the unit and the applicability of the daily generation plan, so as to be more adaptable to the uncertainty of wind power and decrease the impact of the uncertainty of wind power on the grid.